JP3341857B2 - Manufacturing method of solid lubricated rolling bearing - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a solid lubricated rolling bearing which is used in a vacuum and in a clean environment with low dust generation.

[0002]

2. Description of the Related Art Conventionally, for lubricating a vacuum bearing, solid lubrication is performed by ion-plating Ag on the transfer surface of an inner ring or an outer ring or the surface of a rolling element or by sputtering MoS ₂ (for example, JP-A-53-138989) is disclosed. Also, for longer life and low dust generation,
Polytetrafluoroethylene (PTF)
E), MoS ₂ , polyetheretherketone (PEE)
K) A material composed of a composite of a resin and an aramid fiber and having self-lubricating properties, and in which a lubricant is supplied from a retainer (for example, Japanese Patent Application Laid-Open No. 4-102718) is disclosed.

[0003]

However, in the bearing having the above structure, a solid lubricating film is applied to either or both of the transfer surfaces and the rolling elements of the inner ring and the outer ring. Since it has a concave surface or a spherical surface, and the processed film thickness lacks uniformity, a film process that is slightly thicker than a necessary thickness is generally performed. Since the excessively adhered solid lubricating film is separated during rotation of the bearing, there is a problem that a large amount of dust is generated. Accordingly, an object of the present invention is to provide a solid lubricated bearing in which a large amount of dust generated at the beginning of rotation is reduced.

[0004]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a composite lubricant containing a solid lubricant containing a solid lubricant film on at least one of a transfer surface of an inner ring and an outer ring and a surface of a rolling element. In the method for manufacturing a rolling bearing having a cage made of a material, the atmospheric pressure is 1 × 10 ⁻⁶ to 1 ×.
Under 10 ² Pa, the ratio of the dynamic equivalent load to the basic dynamic load rating applied to the bearing is set to 1.0 to 3.9%, and the total number of rotations of the bearing is set to 1.0 × 10 ^{5 to 3.5.} A running-in operation in a range of × 10 ⁶ times and a rotation speed of 3000 rotations per minute or less . In addition, the above-mentioned running-in operation is performed in 3.
After performing 5 × 10 ⁶ times, reverse the direction of the load applied to the bearing
Then, re-running operation by 10-50% of previous operation speed
May be.

[0005]

When the bearing is used in a vacuum device or the like, since the sputtered film of MoS ₂ that has excessively adhered is removed in advance by running the bearing under the above processing conditions.
A large amount of dust generated at the beginning of rotation can be prevented.

[0006]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. FIG. 1 is a side sectional view showing a processing apparatus used in the present invention. In the figure, a motor unit 3 is a cylindrical frame 31.
And a stator 32 fixed to the inside thereof, a rotor 33 provided inside the stator 32 via a gap, and brackets 34 and 35 detachably provided at both ends of the frame 31. The brackets 34, 35 are provided with housing portions 36, 37 for mounting the bearing 1, and rotatably support the rotor 33 via the bearing 1. A spring cover 4 is attached to one of the brackets 34, and a spring 6 is inserted between the spring cover 4 and the bearing 1 via a holding ring 5.
An axial load in a fixed direction is always applied to the bearing 1. The other bracket 35 is provided with a cover 7 having a compatible mounting portion so that it can be replaced with the spring cover 4. FIG. 2 is a side view of a main part of the bearing 1 used in the present invention. 11 is an inner ring, 12 is an outer ring, 1
Numeral 3 is a rolling element, and numeral 14 is a cage made of a composite material of PTFE, MoS ₂ , PEEK resin and aramid fiber. On the transfer surfaces of the inner ring 11 and the outer ring 12 and the surfaces of the rolling elements 13, a 0.5 μm-thick MoS ₂ sputtering film 15 is applied. Of the sputtered film 15, the effective layer 16, which is a film that firmly adheres to the surface of the material and performs a lubricating action, has a very small thickness, and most of the remaining film is peeled off at the beginning of rotation of the bearing 1. It becomes dust and becomes a cause of contaminating a vacuum device using the bearing 1 and a processing object. Now, the bearing 1 shown in FIG. 2 was processed using the processing device 2 under the following conditions. The bearing uses a deep groove ball bearing of model number # 608, applies an axial load of 60N by a spring 6, and rotates for 30 hours at a rotational speed of 1200 rpm in an environment of an atmospheric pressure of 1 × 10 ^-4 Pa and a temperature of 20 ° C. I let it. The ratio P / C of the dynamic equivalent load (P) to the basic dynamic load rating (C) at this time.
Is 3.9%. This P / C was determined based on the method of calculating the dynamic load rating and the rated life of the rolling bearing of Japanese Industrial Standards (JIS) (B1518). Assuming that the radial load is Fr and the axial load is Fa, the dynamic equivalent load is represented by P = XFr + YFa. In the case of the bearing 1 of the present embodiment, the radial load coefficient X = 0.56 and the axial load coefficient Y = 1.71. , And C = 2635N. Here, assuming that the radial load can be ignored,
Since Fr = 0 and the axial load is 60N,
Fa = 60N. From the above, P = XFr + YF a =
0.56 × 0 + 1.71 × 60N = 102.6N Therefore, P / C = 102.6 / 2635 × 100 = 3.9
%.

FIG. 3 shows a state of the bearing 1 after the end of the running-in operation process. MoS ₂ sputtered film 1 adhering to the transfer surfaces of inner ring 11 and outer ring 12 and the surface of rolling element 13
5 is peeled off, and a transfer film 17 formed by a lubricant supplied from the holder 14 is formed on the execution layer 16 which is firmly adhered. Next, the amount of dust generated after the running-in operation was measured by the dust amount measuring device 8 shown in FIG. In the dust generation amount measuring device 8, the spring 6 of the processing device 2 is disposed above, and the bearing 1 can be viewed from below, and a laser type counter 81 is provided below the bearing 1, so that the above environment and load conditions are satisfied. The bearing 1 is rotated under the same leveling operation processing conditions, and the number of particles (particles) having a particle diameter of 0.38 μm or more that have separated and fallen from the sputtered film from the bearing 1 is counted for 5 minutes to obtain a relative dust generation amount. I did it. Figure 5 is to if the
Particles during operation processing are collected by the dust amount measurement device 8
The counted progress is shown. 1000 pieces immediately after starting operation
The relative dust generation amount of the above / 5 minutes was about 1 hour
At the level of 10 to 100 pieces / 5 minutes. About 1
After 2 hours, change to the level of 0 to 10 pieces / 5 minutes.
It can be seen that the number has decreased. At this level, the amount of dust generated is
Applies when used in environments where relatively high levels are allowed
Is done. FIG. 6 shows the progress of counting the particles in the same manner as described above by rotating the bearing in the reverse direction after performing the smoothing operation 3.5 × 10 ⁶ times . . As a result, the bearing after the running-in operation process was rotated for 3 hours after the start of rotation.
At around (10% of the running-in operation time) , the relative amount of dust is not recognized, and it can be seen that almost no dust is generated from the bearing. This level requires extremely low dust generation.
Applies when used in the required environment. In addition, assuming that the axial load is 15 N, the other processing conditions are the same as the above case, and the P / C = 1.3%, the particles subjected to the running-in process are counted by the dust generation amount measuring device 8 to count particles. As a result, the number of particles of 10 to 30/5 minutes was counted, and it was found that there was an effect of reducing the amount of dust generation. However, with an axial load of 10N, P / C
= 0.9%
As a result of counting the particles by the dust amount measuring device 8, the number of particles of 50 to 100/5 minutes is counted, and the particles are used in an environment where the dust amount is relatively high.
Found to be suitable when In addition, in the same smoothing operation processing, the operation was performed at a rotation speed of about 3000 rpm for 20 hours (3.6 × 10 ⁶ times), but the total rotation speed was 1.0 ×
Although the amount of dust generation was small in the range of 10 ^{5 to 3.5} × 10 ⁶ times, it was found that the life of the bearing was shortened when the bearing was actually used after the run-in operation when the range was more than this range.
If the rotation speed increases , the temperature rises and the amount of dust
An adverse effect such as an increase or shortening of the service life is considered. Accordingly
The rotation speed during running-in should be less than 3000 rpm
Good. Further, the atmospheric pressure is desirably a vacuum state which is not affected by oxidation or humidity, and is preferably in a range of 1 × 10 ⁻⁶ to 1 × 10 ² Pa where the solid lubricated rolling bearing is actually used. From the processing conditions and the results of the above embodiment, the running-in processing conditions of the present invention are as follows: the atmospheric pressure is in the range of 1 × 10 ⁻⁶ to 1 × 10 ² Pa; the load applied to the bearing is the basic dynamic load rating (C ) And the ratio P / C to the dynamic equivalent load (P) is 1.0 to 3.9.
%, And the total number of rotations is 1.0 × 10 ^{5 to 3.5} × 10 ^6.
Any number of times is acceptable. In addition, the above
After 3.5 × 10 ⁶ times, was measured by dust amount measuring device 8 to reverse bearing, 10 hours (7.2 × 1
0 ⁴ times), the was counting the number of 10 to 30/5 minutes of the particles. 15 hours (1.08 × 10 ⁵ times, running-in
(Time ratio of 50%), the number of particles was reduced to 0 to 10/5 minutes, and it was found that there was an effect of further reducing the amount of generated particles. From the above, when the bearing rotates in both the forward and reverse directions, after rotating forward at the same rotational speed for 30 hours, the direction of the load applied to the bearing is reversed, and the rotational speed is 10 to 50% of the forward rotational speed. It turns out that we should drive again. As described above, by running the bearing under the above-described processing conditions, the sputtered film of MoS ₂ that has excessively adhered is removed in advance. Can be prevented. Therefore, by incorporating and using the bearing in an actual vacuum device after the above-mentioned smoothing operation process is completed, dust is hardly generated after assembling, and a clean environment can be maintained.

[0008]

As described above, according to the present invention, the sputtered film of MoS ₂ which has excessively adhered to the transfer surfaces of the inner and outer rings of the bearing and the surfaces of the rolling elements in advance is removed. When assembled, a large amount of dust generated at the beginning of rotation can be prevented, and there is an effect of preventing contamination in a vacuum and in a clean environment.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing a processing apparatus according to an embodiment of the present invention.

FIG. 2 is a side view of a main part of a bearing before processing according to the present invention.

FIG. 3 is a side view of a main part of a bearing after processing according to the present invention.

FIG. 4 is a side sectional view showing a dust generation amount measuring apparatus according to an embodiment of the present invention.

FIG. 5 is an explanatory diagram showing the progress of a dust generation amount during a running-in operation process of the present invention.

FIG. 6 is an explanatory diagram showing the amount of dust generated when a bearing that has been subjected to the running-in operation processing of the present invention is attached to an actual device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Bearing 11 Inner ring 12 Outer ring 13 Rolling element 14 Cage 15 Sputtered film 16 Effective layer 17 Transfer film 2 Processing device 3 Motor part 32 Stator 33 Rotor 34, 35 Bracket 4 Spring cover 5 Pressing ring 6 Spring 8 Dust amount measurement Equipment 81 Counter

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁷ , DB name) F16C 19/00-19/56 F16C 33/30-33/66

Claims (2)

(57) [Claims] 1. A method for manufacturing a rolling bearing having a cage made of a composite material containing a solid lubricant, wherein a solid lubricating film is formed on at least one of a transfer surface of an inner ring and an outer ring and / or a surface of a rolling element. When the pressure is 1 × 10 ⁻⁶ to 1 × 10 ² Pa, the ratio of the dynamic equivalent load to the basic dynamic load rating applied to the bearing is set to 1.0 to 3.9%, and the total number of rotations of the bearing is 1.
0 × 10 ^{5 to 3.5} × 10 ⁶ times and rotation speed
Characterized in that the smoothing operation is performed at 3000 rpm or less . 2. After the smoothing operation is performed 3.5 × 10 ⁶ times , the direction of the load applied to the bearing is reversed, and the smoothing operation is performed again by 10 to 50% of the operating rotation speed. The manufacturing method of the solid lubricated rolling bearing according to the above.